Field of Disclosure
Certain aspects of the claimed invention generally relate to dynamically configuring one or more cells based on signal quality measurements received from all antennas of a receiver-limited UE capable of operating in a CA mode.
Description of Related Art
Wireless communication networks are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcasts, and so on. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources. For example, one network may be a 3G (the third generation of mobile phone standards and technology) system, which may provide network service via any one of various 3G radio access technologies (RATs) including EVDO (Evolution-Data Optimized), 1×RTT (1 times Radio Transmission Technology, or simply 1×), W-CDMA (Wideband Code Division Multiple Access), UMTS-TDD (Universal Mobile Telecommunications System-Time Division Duplexing), HSPA (High Speed Packet Access), GPRS (General Packet Radio Service), or EDGE (Enhanced Data rates for Global Evolution). The 3G network is a wide area cellular telephone network that evolved to incorporate high-speed internet access and video telephony, in addition to voice calls. Furthermore, a 3G network may be more established and provide larger coverage areas than other network systems. Such multiple access networks may also include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier FDMA (SC-FDMA) networks, 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) networks, and Long Term Evolution Advanced (LTE-A) networks.
A wireless communication network may include a number of base stations that can support communication for a number of mobile stations. A mobile station (MS) may communicate with a base station (BS) via a downlink and an uplink. The downlink (or forward link) refers to the communication link from the base station to the mobile station, and the uplink (or reverse link) refers to the communication link from the mobile station to the base station. A base station may transmit data and control information on the downlink to a mobile station and/or may receive data and control information on the uplink from the mobile station.
A mobile station may have several receivers and antennas, which may be shared by different applications and/or frequency bands. A receiver-limited mobile station may refer to a mobile station in which a number of receivers is less than or equal to a number of antennas (N). Receiver-limited mobile stations may operate in M×N multiple-input multiple-output (MIMO) in a non-carrier aggregation (CA) mode, where M represents the number of antennas at a transmitting device. However, because the mobile station is “receiver-limited,” it may only support M×(N/2) MIMO in CA.
In a receiver-limited UE, once CA is configured and activated, there may be no mechanism to check if the rank has improved on a primary cell (Pcell) because the receivers are assigned to a secondary cell (Scell), or vice versa. Under such circumstances, the network may not be utilizing the spatial multiplexing gain available and may be unnecessarily tying-up resources on the Scell.
Since M×N MIMO on either the Pcell or Scell may be preferred, what is needed are techniques and apparatus to detect a receiver-limited UE and activate and/or deactivate one or more cells accordingly.